1. Field of the Invention
The present invention generally relates to a wire guide for a fuel injector and, more particularly, to a wire guide used to route solenoid wires around a control valve of a fuel injector and between rocker arm assemblies.
2. Background Description
Fuel injected engines are designed for both efficiency and longevity. These efficiencies range from the materials used to construct the engines to the fuel injectors used in the engines, themselves. In current engine designs, the fuel injectors are placed beneath valve covers of the engine in order to inject fuel into the combustion chamber.
In general, the fuel injector includes a driver which delivers a current or voltage to an open side of an open coil solenoid. The magnetic force generated in the open coil solenoid will shift a spool into the open position so as to align grooves or orifices (hereinafter referred to as xe2x80x9cgroovesxe2x80x9d) of the control valve body and the spool. The alignment of the grooves permits the working fluid (i.e., hydraulic fluid) to flow into an intensifier chamber from an inlet portion of the control valve body. The high pressure fluid then acts on an intensifier piston which compresses fuel located within a high pressure plunger chamber. As the pressure in the high pressure plunger chamber increases, the fuel pressure rises above a needle check valve opening pressure. At the prescribed fuel pressure level, the needle check valve will shift against a needle spring and open the injection holes in a nozzle lip for injection.
At the end of the cycle, the driver will deliver a current or voltage to the closed coil solenoid. The magnetic force generated in the closed coil solenoid will shift the spool into the closed position so as to align grooves of the spool with ejection or discharge ports of the control valve body. This alignment permits the working fluid to flow from the intensifier chamber, through the discharge ports and then be ejected from the control valve body, via the discharge ports. The discharge of the working fluid is at a high pressure. Once the working fluid is discharged, it is captured and reused by the injector.
To control the fuel injectors, solenoid wires are coupled between the driver and the respective open side coil solenoid and the closed side coil solenoid. These solenoid wires deliver the current or voltage from the driver to the respective open coil solenoid and the closed coil solenoid. In this manner, the generated magnetic forces are able to shift the spool between the open and closed positions. However, these solenoid wires are routed over the discharge ports and adjacent the rocker arm assemblies of the engine. The wire harness assemblies for the solenoid wires are also located adjacent the rocker arm assemblies in such a manner that the solenoid wires must bridge the gap between the open and closed coil solenoid and the wire harness assembly (which is approximately 150 mm). In such a harsh environment, the solenoid wires are subject to failure which may arise from, for example,
1. vibrations caused by the rocker arm assemblies,
2. chaffing or striking from the rocker arm assemblies, and
3. vibrations caused when the working fluid is discharged from the fuel injectors.
These factors, over time, lead to a failure of the fuel injector. This, of course, adversely affects the efficiency of the engine and, in instances, may result in a catastrophic failure of the engine. In this manner, the engine is not designed for efficiency.
The present invention is directed to overcoming one or more of the problems as set forth above.
In a first aspect of the present invention, a wire guide includes a body having an opening adapted to conform to a shape of a control valve body of a fuel injector. A first channel is provided on a first side of the body and an extension extends from a second, opposing side of the body. A second channel is formed on the extension. At least one clip is formed on a periphery of the body between the first channel and the second channel. In embodiments, the at least one clip includes opposing walls and a member extending between the opposing walls. The opposing walls and the extending member form a passageway for securing at least one solenoid wire therebetween. At least two projections may inwardly extend from a wall which defines the opening. And, rounded protuberances may extend from an underside of the body at opposing sides thereof.
In a second embodiment, the wire guide includes a body having an opening adapted to conform to a shape of a control valve body of a fuel injector, first and second channels and an extension extending from the body on a second, opposing side. The second channel is formed on the extension. A first and a second clip are formed on the periphery of the body between the first channel and the second channel. At least two projections inwardly extend from a wall which defines the opening. The projections engage a groove or grooves of the fuel injector. In embodiments, the first clip includes opposing wall members and a member extending between the opposing wall members. The opposing wall members and the extending member form a passageway for securing at least one solenoid wire therebetween. The second clip includes opposing walls and a space formed therebetween, and a projection extending from one of the opposing walls in order to maintain the at least one solenoid wire within the space. In further embodiments, downward extending protrusions extend from the body and a slot is provided in one of the downward extending protrusions. Rounded protuberances may also extend from an underside of the body at opposing sides thereof
In still another embodiment, a fuel injector is provided. The fuel injector includes a control valve body, an intensifier housing and at least one groove formed on one of (i) the control valve body, (ii) the intensifier housing and (iii) between the control valve body and the intensifier housing. A nozzle assembly is coupled to the intensifier housing. A wire guide is coupled to the control valve body. The wire guide includes a body having an opening adapted to conform to a shape of the control valve body, a first and second channel and an extension. The second channel is formed on the extension. A first clip is formed on a periphery of the body between the first channel and the second channel and at least two projections inwardly extend from a wall which defines the opening and further engage the at least one groove. The first channel and the second channel route at least one solenoid wire away from discharge ports of the control valve body and rocker arm assemblies of an engine, and the clip retains the at least one solenoid wire about a periphery of the body and the control valve body.